Synthesis and Evaluation of Oxidation Stability of Biodiesel Prepared from Spent Bleaching Clay Residual Oil

Energy plays a key role in each sector of life ranging from basic needs to better standards of life. The world is concerned about 3 ps (population, poverty, and pollution). The increase of these three factors has led the search of the best alternative sources of energies to fulfill all needs of a modern way of life. Biodiesel is a sustainable energy source that has proved to be the best alternate of mineral diesel that possesses similar properties as found in mineral diesel. The recent trend in biodiesel research is towards the use of very cheap feedstock to make this substitute more economical. Following this similar trend, the attempt is made to produce biodiesel from less expensive feedstock namely; residual oil of spent bleaching clay (SBC). In the first step, the quantity of the residual oil that can be recovered followed by assessing its quality was investigated. Afterward, a two-step method of the transesterification process was employed to enhance the yield of methyl ester. The highest yield of 85% was obtained. Key fuel properties were measured and found in good agreement with ASTMD 6751 standards limits. The study also concerned with the practical availability of biodiesel in terms of its stability. For this purpose, produced biodiesel was evaluated for its oxidation stability during 90 days of storage by FT-IR and rancimat methods.